function add(a, b, c) {
    return a + b + c;
}

const curriedAdd = curry(add);
expect(curriedAdd(1, 2, 3)).to.equal(6);
expect(curriedAdd(1, 2)).to.be.a('function');
expect(curriedAdd(1)(2)).to.be.a('function');
expect(curriedAdd(1)(2)(3)).to.equal(6);
expect(curriedAdd(1, 2)(3)).to.equal(6);
expect(curriedAdd(1)(2, 3)).to.equal(6);
expect(curriedAdd(1, 2)(3, 4)).to.equal(6);
